US4082160A - Silencer for exhausting gas streams - Google Patents

Silencer for exhausting gas streams Download PDF

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Publication number
US4082160A
US4082160A US05674994 US67499476A US4082160A US 4082160 A US4082160 A US 4082160A US 05674994 US05674994 US 05674994 US 67499476 A US67499476 A US 67499476A US 4082160 A US4082160 A US 4082160A
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Prior art keywords
air
silencer according
air permeability
insert
silencer
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Expired - Lifetime
Application number
US05674994
Inventor
Hermann Schilling
Heinz Seifert
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Freudenberg Carl KG
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Freudenberg Carl KG
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
    • F01N13/16Selection of particular materials
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00Silencing apparatus characterised by method of silencing
    • F01N1/08Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
    • F01N1/10Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling in combination with sound-absorbing materials

Abstract

A silencer for reducing the noise of an exhausting gas stream, comprising a hollow body having a connector, a sound-absorbing insert in the body and an inner component, the sound-absorbing insert comprising at least one split sheet of closed-pore foamed plastic material having a thickness of less than its average pore-size. Advantageously the sheet material comprises closed-pore cross-linked foamed polyethylene stacked or wound to provide about 3 to 30 layers, each layer ranging in thickness from about 0.1 to 1.0 mm, having an average pore diameter from about 0.2 to 2 mm and an air permeability from about 0.5 to 200 Rayl, the air permeability of the innermost layer ranging from about 1 to 4 times the air permeability of the outermost layer.

Description

This invention relates to silencers for reducing the blow-out noises of gas streams, for use for example with compressed air valves. The silencers are of the kind comprising a hollow body having a connector, a sound-absorbing insert in the body and an inner component. In compressed air valves, venting connections are frequently provided with such silencers, because the expanding compressed air produces loud noises.

The usual effect of such silencers is that an initially sharply beamed air jet is passed through a mass of porous material by which it is diffused in a stream of large cross-section. Thus there is a reduction in the air speed and thus also in the noise production, this being in the ratio of the cross-sectional area of the air jet to the free passage area of the porous material. A prerequisite for this however is that there should be a uniform distribution of the air flow across the larger cross-section. In very finely porous material, this is achieved even with fairly small thicknesses of material but with coarsely porous material it is only achieved by a correspondingly increased thickness of material, since all materials are traversed in a more or less linear manner. This applies equally to sintered materials of metal or polyethylene powder, to open-pore foam, and to felt.

It follows from this that, for an equivalent degree of sound absorption, silencers comprising finely porous inserts can be smaller than silencers having coarsely porous inserts. It should however be remembered that finely porous inserts produce undesired throttling of the air flow if they are even slightly dirty or oily.

Existing forms of the insert consist of a rolled up sheet of wire mesh and a cartridge of air-permeable, porous foam material.

Both these inserts have basically an open-pore character and it is from this that their disadvantages result. If they are finely constructed, both are sensitive to fouling and oiling up, and they are therefore restricted to being of substantial size.

The aim of the present invention is to provide a silencer of the kind described when even when made of smaller size than is customary still has good sound-absorption properties and is not easily fouled or oiled up.

To this end, according to this invention, the sound-absorbing insert of such a silencer is made of one or more split sheets of closed-pore foamed plastics material, the thickness of the, or each, split sheet being less than its average pore size.

THE DEGREE OF SOUND-ABSORPTION AND THE RESISTANCE TO FOULING CAN BE IMPROVED BY FORMING THE INSERT WITH A NUMBER OF LAYERS FORMED BY SUPERIMPOSED SHEETS OR SHEETS WOUND IN LAYERS. The sheets may have differing air permeabilities from each other. The air permeability of the insert may be uniform from one side to the other, or may increase or decrease. Particularly outer layers may have a lower air permeability than inner layers.

the resistance to fouling and oiling-up of a silencer made in accordance with the invention may be substantially better than that of existing silencers of the same kind. In tests, a high dirt loading with oil and floating particles of a stream of air passing through the silencer resulted neither in a clear reduction in the sound absorption nor in a clear increase in the throttling effect of the silencer. This means that the insert has a self-cleaning action. Washing out of the sound-absorbing insert thus becomes superfluous and its operating life is improved.

The reason for this is that in a sound absorbing insert in accordance with the invention, an appreciable portion of the pores have gas regularly flowing across them but not through them. These are those pores which are cut open on one side as the sheet is sliced. Foreign substances such as oil and dirt are precipitated preferentially in these voids, through which there is no flow. The solid constituents do not however form permanent encrustations there. Instead, as further air flows past, these substances are swept out again and are carried out by the air flow through those large pores which are cut open on both sides as the sheet is sliced. The very large difference in volume of the pores cut open on one side also has an energy dissipating and balancing effect upon the air flowing past them. Preferably, the sheet or sheets are of a cross-linked polyolefin, for example polyethylene.

The insert may be supported externally by an air-permeable plate or sleeve forming part of the body. It may also surround a radially perforated tube, which forms the inner component, the total area of the perforations being greater than the cross-sectional area of the tube.

An example of a silencer in accordance with the invention will now be described with reference to the accompanying drawings in which:

FIG. 1 is a longitudinal section through the silencer;

FIG. 2 is a cross-section to a much larger scale through a split sheet of closed-pore foamed plastic material from which the insert of the silencer is made; and

FIG. 3 is a section through the insert which consists of a number of sheets as shown in FIG. 2.

The silencer has a body 1 which is a molding of metal or plastic material and has a screw-threaded connector portion 11 and an air-permeable perforated cage portion 12.

An inner component 2 is screwed into the body 1 and a sound absorbing insert 3 is clamped in a sealing manner between axially facing surfaces 31 and 32 of the inner component and the body respectively.

An important feature of the inner component 2 is the permeability to air of a perforated tubular part 21 of the component 2. This must be greater in the radial direction 22 than in the axial direction 23, and the perforations 24 should be uniformly distributed over its surface.

Referring to FIG. 2, the thickness 33 of the split sheet is less than the average pore diameter 34. The result is that a portion of the pores 35 are cut open on both sides, so that the sheet becomes permeable to the air. For a given pore size, the degree of permeability to air can be determined by the sheet thickness 33. It is however also possible, for a predetermined sheet thickness, to determine the permeability to air by an intentional adjustment of the pore size.

Referring to FIG. 3, it will be evident that the air flowing through the insert is compelled to flow in a meandering manner, whereby the distance travelled by the air in its passage through the insert is considerably greater than the thickness of the insert and also considerably greater than with conventional inserts of the same thickness. To achieve a predetermined sound absorption characteristic, a small total thickness of the insert is therefor sufficient, in spite of the relatively large pores.

The advantages obtained by the invention consist particularly in that the silencer achieves a predetermined reduction in noise for a smaller overall size than conventional silencers of the same kind, and that it is considerably more insensitive to oil and dirt.

The thickness of the sheets generally ranges from about 0.1 to 1 mm and preferably from about 0.4 to 0.6 mm and the pores generally average from about 0.2 to 2 mm and preferably from about 0.8 to 1.2 mm in diameter. The ratio of average pore diameter to sheet thickness generally ranges from 1.5:1 to 3:1. As employed hereinabove, the average pore diameter can be determined approximately by a measuring microscope, by applying to the sheet surface a measured amount of liquid and seeing how much surface area is moistened, or equivalent known procedures. The sheets may range in air permeability from about 0.5 to 200 Rayl and preferably from about 4 to 10 Rayl, determined according to DIN52213.

Advantageously the number of superposed layers of sheets is from about 3 to 30, generally from about 6 to 15. Their air permeabilities may be approximately equal or the innermost layer may be of higher permeability than the outermost, e.g. about twice as high and possibly about four or more times as high.

While the preferred material is polyethylene, polypropylene, other polyolefins and other polymer foams also may be used. If the polymer is not already cross-linked as formed, it may have been cross-linked with dicumyl peroxide or other equivalent peroxides, by radiation, or the like.

A preferred embodiment is described in the following example:

EXAMPLE

A silencer as shown in FIG. 1 is provided for an exhaust gas outlet having an internal radius of about 6 mm. There are provided 7 layers of a cross-linked polyethylene foam sheet having a thickness of 0.5 mm, an average pore diameter of 1 mm and an air permeability at 6 bars of 1.5 m3 /minute. The outside diameter of the insert was 17 mm and its length in axial direction was 40 mm. Provision of the silencer reduced the noise level 1 meter from the gas outlet from an original level of 104 decibels to 75 decibels.

It will be appreciated that the instant specification and examples are set forth by way of illustration and not limitation, and that various modifications and changes may be made without departing from the spirit and scope of the present invention.

Claims (12)

What we claim is:
1. A silencer for reducing the noise of an exhausting gas stream, comprising a body having a connecter portion and an air permeable portion, a sound-absorbing insert in the body and an air permeable inner component, the sound-absorbing insert comprising at least one split sheet of closed-pore foamed plastic material having a thickness of less than its average pore-size.
2. A silencer according to claim 1, in which the sheet is a closed-pore foamed polyolefin.
3. A silencer according to claim 1, in which the sheet is a cross-linked foamed polyolefin.
4. A silencer according to claim 2, in which the polyolefin is polyethylene.
5. A silencer according to claim 1, in which the insert has a number of layers formed by superimposed sheets.
6. A silencer according to claim 5, in which the sheets are of different air permeabilities from each other, the outermost layer having a lower air permeability than the innermost layer.
7. A silencer according to claim 1, in which the insert is supported externally by the air-permeable portion comprising a plate or sleeve.
8. A silencer according to claim 1, in which the insert surrounds a radially perforated tube which forms the air permeable inner component, the total area of the perforations being greater than the cross-sectional area of the tube.
9. A silencer according to claim 8, in which the sheet comprises closed-pore cross-linked foamed polyethylene, about 3 to 30 layers being provided, each layer ranging in thickness from about 0.1 to 1.0 mm, having an average pore diameter from about 0.2 to 2 mm and an air permeability from about 0.5 to 200 Rayl, the air permeability of the innermost layer ranging from about 1 to 4 times the air permeability of the outermost layer.
10. A silencer according to claim 9, about 6 to 15 layers being provided, each layer ranging in thickness from about 0.4 to 0.6 mm, having an average pore diameter from about 0.8 to 1.2 mm and an air permeability from about 4 to 10 Rayl, the air permeability of the innermost layer ranging from about 1 to 2 times the air permeability of the outermost layer.
11. A silencer according to claim 1, in which the insert has a number of layers formed by a sheet wound in layers.
12. A silencer according to claim 11, in which the sheets are of different air permeabilities from each other, the outermost layer having a lower air permeability than the innermost layer.
US05674994 1975-04-16 1976-04-08 Silencer for exhausting gas streams Expired - Lifetime US4082160A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DT2516626 1975-04-16
DE19752516626 DE2516626C2 (en) 1975-04-16 1975-04-16 Schalldaempfer of outlet pressure gases

Publications (1)

Publication Number Publication Date
US4082160A true US4082160A (en) 1978-04-04

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US05674994 Expired - Lifetime US4082160A (en) 1975-04-16 1976-04-08 Silencer for exhausting gas streams

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US (1) US4082160A (en)
JP (1) JPS5913039B2 (en)
DE (1) DE2516626C2 (en)
FR (1) FR2307959B1 (en)
GB (1) GB1480006A (en)

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4263981A (en) * 1979-01-31 1981-04-28 Allied Chemical Corporation Vacuum pump exhaust muffler
US4482027A (en) * 1983-08-29 1984-11-13 Gould William A Acoustic trap for discharging fire arms
US5097924A (en) * 1988-06-08 1992-03-24 Mcneil (Ohio) Corporation Muffler for a compressed air driven motor
US5767459A (en) * 1996-11-18 1998-06-16 Ingersoll-Rand Company Muffler for pneumatic devices
WO1999036679A1 (en) * 1998-01-13 1999-07-22 Robert Earl Sterling Pneumatic hand tool exhaust muffler
WO2000075495A1 (en) * 1999-06-02 2000-12-14 3M Innovative Properties Company Muffler with acoustic absorption insert for limited clearance pneumatic device applications
US6209678B1 (en) 1998-01-13 2001-04-03 Robert E. Sterling Pneumatic hand tool exhaust muffler
FR2834313A1 (en) * 2001-12-27 2003-07-04 Acoustique Ind Sarl Soc D gas expansion silencer device
US6668971B2 (en) 1998-01-13 2003-12-30 Robert E. Sterling Pneumatic hand tool exhaust muffler having inner and outer tubes
US20040055815A1 (en) * 1998-01-13 2004-03-25 Sterling Robert E. Muffler for pneumatic hand tool
US20040079582A1 (en) * 2002-10-29 2004-04-29 Dondi Beda Charles Muffler for suction system exhaust air used with an automatic cutting machine
US20040231913A1 (en) * 2003-05-21 2004-11-25 Mccombs Norman R. Noise muffler for oxygen concentrator
WO2006075670A1 (en) 2005-01-13 2006-07-20 Smc Kabushiki Kaisha Silencer
US20060237081A1 (en) * 2005-04-21 2006-10-26 Ingersoll-Rand Company Double throat pulsation dampener for a compressor
US7216739B2 (en) 1998-01-13 2007-05-15 Exhaust Technologies, Inc. Muffler for pneumatic hand tool
US20090090530A1 (en) * 2007-07-13 2009-04-09 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US20090294211A1 (en) * 2008-05-28 2009-12-03 Longyear Tm, Inc. Noise reducing device for a pneumatic tool
KR100948973B1 (en) 2008-06-30 2010-03-23 (주)한창산업 Cassette type silencer
US20100089689A1 (en) * 2007-03-08 2010-04-15 Ho-Young Cho Silencer for pneumatic device
US20110126541A1 (en) * 2009-12-02 2011-06-02 Longyear Tm, Inc. Muffler system for noise abatement and ice control
US20120017565A1 (en) * 2010-07-22 2012-01-26 Gerd Gaiser Exhaust system
US20120202407A1 (en) * 2011-02-04 2012-08-09 Phuong Taylor Nguyen Air Blast Blowdown Silencer System for Blast Pot
JP2013000195A (en) * 2011-06-13 2013-01-07 Air Water Safety Service Inc Nozzle structure
US9381637B1 (en) * 2015-03-23 2016-07-05 Storm Pneumtic Tool Co., Ltd Compressed air tool having silencer structure
RU2599216C1 (en) * 2015-08-26 2016-10-10 Олег Савельевич Кочетов Multi-section silencer
RU2600188C1 (en) * 2015-09-08 2016-10-20 Олег Савельевич Кочетов Multi-section noise suppressor
RU2641993C1 (en) * 2016-10-10 2018-01-23 Олег Савельевич Кочетов Multi-section noise suppressor
RU2641991C1 (en) * 2016-10-10 2018-01-23 Олег Савельевич Кочетов Multi-section silencer
RU2652843C2 (en) * 2016-03-18 2018-05-03 Татьяна Дмитриевна Ходакова Multi-section silencer
RU2666705C1 (en) * 2017-10-06 2018-09-11 Олег Савельевич Кочетов Multi-section silencer

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6185520A (en) * 1984-10-03 1986-05-01 Kazuyasu Kotani Muffler
JPS61110597U (en) * 1984-12-25 1986-07-12
JPH03127440U (en) * 1990-03-31 1991-12-20
DE9317376U1 (en) * 1993-11-12 1994-03-17 Wilms Peter Device for sound damping in a silo vehicle

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2764250A (en) * 1953-01-23 1956-09-25 Jeffords Joseph Silencer for pneumatic devices
US3009531A (en) * 1958-08-01 1961-11-21 Theodore E Mead Muffler
US3688870A (en) * 1971-08-26 1972-09-05 Stephen J Gibel Through-flow aspirator muffler
US3715010A (en) * 1972-02-02 1973-02-06 S Gibel Multiple collimator muffler
US3882961A (en) * 1974-04-01 1975-05-13 Servicemaster Ind Muffler for vacuum-inducing motor

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1471627A (en) * 1966-03-17 1967-03-03 Porous Plastics Ltd advanced silent
US3502171A (en) * 1968-05-31 1970-03-24 Boeing Co Composite laminar structure for noise attenuation of fast moving gas streams,and method of making the same
FR2055030A5 (en) * 1969-07-15 1971-05-07 Dunlop Co Ltd Gas pressure reducing device
DE2232559A1 (en) * 1972-07-03 1974-01-24 Messerschmitt Boelkow Blohm Muffler for reducing the noise produced by gases flowing out

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2764250A (en) * 1953-01-23 1956-09-25 Jeffords Joseph Silencer for pneumatic devices
US3009531A (en) * 1958-08-01 1961-11-21 Theodore E Mead Muffler
US3688870A (en) * 1971-08-26 1972-09-05 Stephen J Gibel Through-flow aspirator muffler
US3715010A (en) * 1972-02-02 1973-02-06 S Gibel Multiple collimator muffler
US3882961A (en) * 1974-04-01 1975-05-13 Servicemaster Ind Muffler for vacuum-inducing motor

Cited By (47)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4263981A (en) * 1979-01-31 1981-04-28 Allied Chemical Corporation Vacuum pump exhaust muffler
US4482027A (en) * 1983-08-29 1984-11-13 Gould William A Acoustic trap for discharging fire arms
US5097924A (en) * 1988-06-08 1992-03-24 Mcneil (Ohio) Corporation Muffler for a compressed air driven motor
US5767459A (en) * 1996-11-18 1998-06-16 Ingersoll-Rand Company Muffler for pneumatic devices
US20040055815A1 (en) * 1998-01-13 2004-03-25 Sterling Robert E. Muffler for pneumatic hand tool
WO1999036679A1 (en) * 1998-01-13 1999-07-22 Robert Earl Sterling Pneumatic hand tool exhaust muffler
US7216739B2 (en) 1998-01-13 2007-05-15 Exhaust Technologies, Inc. Muffler for pneumatic hand tool
US6209678B1 (en) 1998-01-13 2001-04-03 Robert E. Sterling Pneumatic hand tool exhaust muffler
US6668971B2 (en) 1998-01-13 2003-12-30 Robert E. Sterling Pneumatic hand tool exhaust muffler having inner and outer tubes
US6926117B2 (en) 1998-01-13 2005-08-09 Exhaust Technologies, Inc. Muffler for pneumatic hand tool
WO2000075495A1 (en) * 1999-06-02 2000-12-14 3M Innovative Properties Company Muffler with acoustic absorption insert for limited clearance pneumatic device applications
US6202785B1 (en) 1999-06-02 2001-03-20 3M Innovative Properties Company Muffler with acoustic absorption insert for limited clearance pneumatic device applications
WO2003056148A1 (en) * 2001-12-27 2003-07-10 Societe D'acoustique Industrielle Silencer gas expanding device
FR2834313A1 (en) * 2001-12-27 2003-07-04 Acoustique Ind Sarl Soc D gas expansion silencer device
US6880670B2 (en) * 2002-10-29 2005-04-19 Beda Charles Dondi Muffler for suction system exhaust air used with an automatic cutting machine
US20040079582A1 (en) * 2002-10-29 2004-04-29 Dondi Beda Charles Muffler for suction system exhaust air used with an automatic cutting machine
US6935460B2 (en) * 2003-05-21 2005-08-30 Airsep Corporation Noise muffler for oxygen concentrator
US20040231913A1 (en) * 2003-05-21 2004-11-25 Mccombs Norman R. Noise muffler for oxygen concentrator
WO2006075670A1 (en) 2005-01-13 2006-07-20 Smc Kabushiki Kaisha Silencer
US20090266643A1 (en) * 2005-01-13 2009-10-29 Smc Kabushiki Kaisha Silencer
KR100868328B1 (en) * 2005-01-13 2008-11-12 에스엠씨 가부시키 가이샤 Silencer
US7753167B2 (en) * 2005-01-13 2010-07-13 Smc Kabushiki Kaisha Silencer
US9062679B2 (en) 2005-04-21 2015-06-23 Ingersoll-Rand Company Double throat pulsation dampener for a compressor
US7549509B2 (en) 2005-04-21 2009-06-23 Ingersoll-Rand Company Double throat pulsation dampener for a compressor
US20060237081A1 (en) * 2005-04-21 2006-10-26 Ingersoll-Rand Company Double throat pulsation dampener for a compressor
US20100089689A1 (en) * 2007-03-08 2010-04-15 Ho-Young Cho Silencer for pneumatic device
US7681690B2 (en) 2007-07-13 2010-03-23 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US20090090530A1 (en) * 2007-07-13 2009-04-09 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US20100155174A1 (en) * 2007-07-13 2010-06-24 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US7845464B2 (en) 2007-07-13 2010-12-07 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US7735603B2 (en) 2008-05-28 2010-06-15 Longyear Tm, Inc. Noise reducing device for a pneumatic tool
US20090294211A1 (en) * 2008-05-28 2009-12-03 Longyear Tm, Inc. Noise reducing device for a pneumatic tool
KR100948973B1 (en) 2008-06-30 2010-03-23 (주)한창산업 Cassette type silencer
US20110126541A1 (en) * 2009-12-02 2011-06-02 Longyear Tm, Inc. Muffler system for noise abatement and ice control
US8215449B2 (en) 2009-12-02 2012-07-10 Longyear Tm, Inc. Muffler system for noise abatement and ice control
US20120017565A1 (en) * 2010-07-22 2012-01-26 Gerd Gaiser Exhaust system
US8783414B2 (en) * 2010-07-22 2014-07-22 Eberspächer Exhaust Technology GmbH & Co. KG Exhaust system
US20120202407A1 (en) * 2011-02-04 2012-08-09 Phuong Taylor Nguyen Air Blast Blowdown Silencer System for Blast Pot
US8708779B2 (en) * 2011-02-04 2014-04-29 Phuong Taylor Nguyen Air blast blowdown silencer system for blast pot
JP2013000195A (en) * 2011-06-13 2013-01-07 Air Water Safety Service Inc Nozzle structure
US9381637B1 (en) * 2015-03-23 2016-07-05 Storm Pneumtic Tool Co., Ltd Compressed air tool having silencer structure
RU2599216C1 (en) * 2015-08-26 2016-10-10 Олег Савельевич Кочетов Multi-section silencer
RU2600188C1 (en) * 2015-09-08 2016-10-20 Олег Савельевич Кочетов Multi-section noise suppressor
RU2652843C2 (en) * 2016-03-18 2018-05-03 Татьяна Дмитриевна Ходакова Multi-section silencer
RU2641993C1 (en) * 2016-10-10 2018-01-23 Олег Савельевич Кочетов Multi-section noise suppressor
RU2641991C1 (en) * 2016-10-10 2018-01-23 Олег Савельевич Кочетов Multi-section silencer
RU2666705C1 (en) * 2017-10-06 2018-09-11 Олег Савельевич Кочетов Multi-section silencer

Also Published As

Publication number Publication date Type
JPS5913039B2 (en) 1984-03-27 grant
DE2516626C2 (en) 1977-04-28 grant
DE2516626A1 (en) application
GB1480006A (en) 1977-07-20 application
DE2516626B1 (en) 1976-09-09 application
JPS51139301A (en) 1976-12-01 application
FR2307959A1 (en) 1976-11-12 application
FR2307959B1 (en) 1981-12-31 grant

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